Imidazo(4,5-b) quinolinium salts and cyanine,merocyanine and styryl photographic sensitizing dyes derived therefrom



United States Patent US. Cl. 260240.4 13 Claims ABSTRACT OF THE DISCLOSURE Novel imidazo[4,5-b]quinolinium salts are useful as intermediates for preparation new cyanine, carbocyanine, merocyanine and styryl cyanine dyestuffs which are valuable spectral sensitizing dyes for photographic silver halide emulsion layers.

This application is a division of copending US. application Ser. No. 286,450, filed June 10, 1963, now US. Patent 3,326,688 granted June 20, 1967.

This application relates to imidazo[4,5-b1quinolinium salts and more particularly to new cyanine, new merocyanine and new styryl photographic sensitizing dyes derived from imidazo-[4,5-b]quinoliniurn salts.

Certain dyes of the cyanine, the merocyanine and the styryl series are known to extend the sensitivity of photographic silver halide emulsions. New spectral sensitizing dyes are desired.

It is therefore an object of our invention to provide new imidazo[4,5-b1quinolinium salts which are valuable for use as intermediates for making valuable spectral sensitizing dyes for photography.

Another object is to provide valuable spectral sensitizing dyes for photographic silver halide emulsion layers, said dyes including cyanine dyes, merocyanine dyes and styryl dyes derived from our imidazo[4,5-b]quinolinium salts.

Another object is to provide valuable spectral sensitizing dyes which exhibit a marked tendency to form J- aggregates which absorb light of longer wavelength than the non-aggregated dye molecules would and sensitize silver halide emulsions to light of the wavelengths absorbed. Another object is to provide dyes which have sharp cutting light absorption and sensitizing characteristics.

Another object is to provide syntheses for said dyes. Still another object is to provide photographic elements containing at least one hydrophilic colloid layer'containing silver halide and a sensitizing amount of a dye derived from our imidazo[4,5-b1quinolinium salts.

Still other objects will be apparent from a consideration of the following specification and claims.

These and other objects are accomplished according to our invention by making dyes from our new imidazo [4,5-b]quinolinium salts including the intermediates represented by the formula:

3,483,196 Patented Dec. 9, 1969 wherein R represents an alkyl group, e.g., methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, dodecyl, octadecyl, benzyl, phenethyl, etc., and an aryl group, e.g., phenyl, p-tolyl, m-tolyl, 3,4-dichlorophenyl, etc.; R represents an alkyl group, e.g., methyl, ethyl, propyl, butyl, hexyl, cyclohexyl, octadecyl, carboxymethyl, 3-carboxypropyl, 4-carboxybutyl, sulfomethyl, 2-sulfoethyl, 4-sulfobutyl, etc.; R represents an alkyl group, e.g., methyl, B-anilinovinyl, etc.; and X represents an acid anion, e.g., chloride, bromide, iodide, thiocyanate, sulfamate, methyl sulfate, ethyl sulfate, perchlorate, p-toluenesulfonate, etc.

The cyanine dyes of our invention include those represented by the formulas:

II If and III R wherein R; R and X are as defined previously; it represents an integer of from 2 to 4; R represents an alkyl group, e.g., methyl, ethyl, n-propyl, n-butyl, n-amyl, isopropyl, isobutyl, benzyl, fl-hydroxyethyl, fl-acetoxyethyl, etc.; and Z represents the non-metallic atoms required to complete a heterocyclic nucleus such as those selected from the nuclei consisting of those of the thiazole series (e.g. thiazole, 4-methylthiazole, 4-phenylthiazole, 5- methylthiazole, S-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl)thiazole, etc.), those of the benzothiazole series, (e.g. benzothiazole, 4-chl0robenzothiazole, S-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole, 4-rnethylbenzothiazole, 5- methylbenzothiazole, 6-methylbenzothiazole, S-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenz0thiazole, S-phenylbenzothiazole, 4-methoxybenzothiaole, S-methoxybenzothiazole, 6-methoxybenzothiazole, 5-iodobenzothiazole, 6-i0dobenzothiazole, 4-ethoxybenzothiazole, 5- ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-di0xymethylenebenzothiazole, 5- hydroxybenzothiazole, 6 hydroxybenzothiazole, etc.), those of the naphthothiazole series, (e.g. a-naphthothiazole, B-naphthothiazole, 5-methoxy-,8-naphthothiazole, 5- ethoxy-fl-naphthothiazole, 8-methoxy-a-naphthothiazole, 7-methoxy-a-naphth0thiazole, etc.), those of the thionaphtheno-7',6',4,5-thiazole series (e.g. 4-methoxythia naphtheno-7,6,4,5-thiazole, etc.), those of the oxazole series (e.g. 4-methyloxazole, S-methyloxazole, 4-phenyloxazole, 4,5-diphenyl0xazole, 4-ethyloxazole, 4,5-dimethyloxazole, 5phenyloxazole, etc.), those of the benzoxazole series (e.g. benzoxazole, S-chlorobenzoxazole, 5- methylbenzoxazole, S-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, S-methoxybenzoxazole, S-ethoxybenzoxazole, 5-chlo robenzoxazole, 6-methoxybenzoxazole, S-hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.) those of the naphthoxazole series (e.g. a-naphthoxazole, B-naphthoxazole, etc.), those of the selenazole series (e.g. 4-methylselen azole, 4-phenylselenaz0le, etc.), those of the benzoselenazole series (e.g. benzoselenazole, 5-chlorobenzoselenazole, S-methoxybenzoselenazole, S-hydroxybenzoselenazole, tetrahydrobenzoselenazole, etc.), those of the naphthoselenazole series (e.g. a-naphthoselenazole, fl-naphthoselenazole, etc.) those of the thiazoline series (e.g. thiazoline, 4-methylthiazoline, etc.), those of the 2-quinoline series (e.g. quinoline, 3-rnethylquinoline, 5- methylquinoline, 7-methylquinoline, 8-methylquinoline, 6-chloroquinoline, S-chloroquinoline, 6-methoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinoline, 8-hydroxyquinoline, etc.), those of the 4-quino1ine series (e.g. quinoline, fi-methoxyquinoline, 7-methylquinoline, 8-methylquinoline, etc.), those of the l-isoquinoline series (e.g. isoquinoline, 3,4dihydroisoquinoline, etc.), those of the 3-isoquinoline series (e.g. isoquinoline, etc.), those of the 3,3-dialkylindolenine series (e.g. 3,3 dimethylindolenine, 3,3,5 trimethylindolenine, 3,3,7-trimethylindolenine, etc.), the 2- and 4- pyridine series (e.g. pyridine, S-methylpyridine, etc.), those of the imidazole series (e.g., imidazole, l-alkyl imidazole, l-alkyl-4-phenylimidazole, l-alkyl-4,5-dimethylim idazole, etc.), those of the benzimidazole series (e.g. benzimidazole l-alkyl-benzimidazole, 1-alkyl-4,5-dichlorobenzimidazole, etc.) and those of the naphthimidazole series (e.g. 1-a1kyl-u-naphthimidazole, l-alkyl-B-naphthimidazole, 1-alkyl-S-methoxy-B-naphthimidazole, etc.) and m represents the integer 1 or 2.

The styryl dyes of our invention include those represented by the formula:

wherein R; R and X are as defined previously; In represents the integer 1 or 2; and R and R each represents the same or a difierent alkyl group, e.g., methyl, ethyl, 2- cyanoethyl, propyl, butyl, hexyl, etc.

The merocyanine dyes of our invention include those represented by the formula:

wherein R; and R are as defined previously; represents an integer of 2 or 3; and Q represents the non-metallic atoms required to complete a to 6 membered heterocyclic nucleus such as those of the 2-pyrazolin-5-one series (e.g. 3-methyl-l-phenyl-Z-pyrazolin-S-one, l-phenyl- 2 pyrazolin 5 one, 1 (2 benzothiazolyl) 3 methyl-2-pyrazo1in-5-one, etc.), those of the isoxazolone series (e.g. 3-phenyl-5(4H)-isoxazolone, 3methyl-5(4H)- isoxazolone, etc.), those of the oxindole series, (e.g. 1-alkyl-2,3-dihydro-2-oxindoles, etc.), those of the 2,4,6 triketohexahydropyrimidine series (e.g. barbituric acid or 2-thiobarbituric acid as Well as their l-alkyl (e.g. l-methyl l-ethyl, l-propyl, l-heptyl, etc.), or 1,3-dialkyl (e.g. 1,3- dimethyl, 1,3-diethy1, 1,3-di-n-propyl, 1,3-diisopropyl, 1,3- dicyclohexyl, 1,3-di(fi-methoxyethyl), etc.), or 1,3-diary1 (e.g. 1,3-diphenyl, l,3-di(p-chlorophenyl), 1,3-di(p-ethoxycarbonylphenyl), etc.), or l-aryl (e.g. l-phenyl-l-pchlorophenyl, l-p-ethoxycarbonylphenyl), etc.) or l-alkyl- 3-aryl (e.g. 1-ethyl-3-phenyl, l-n-heptyl-3-phenyl, etc.) derivatives), those of the rhodanine series (i.e., 2-thio-2,4- thiazolidinedione series), such as rhodanine, 3-alkylrhodanines e.g. 3-ethylrhodanine, 3- allylrhodanine, etc.) or 3-arylrhodanines (e.g. 3-phenylrhodanine, etc.), etc., those of the 2(3H)-imidazo[1,2-a]pyridone series, those of the 5,7-dioxo-6,7-dihydro-5-thiazolo[3,2-a]pyri-midine series (e.g. 5,7-dioxo-3-pheny1-6,7-dihydro-5-thiazolo[3, 2-a]pyrimidine etc.), those of the 2-thio-2,4-oxazolidinedione series (i.e. those of the 2-thio-2-4(3H,5H)-oxazoledione series) (e.g. 3-ethyl-2-thio-2,4-oxazolidinedione, etc.), those of the thianaphthenone series (e.g. 3-(2H)-thianaphthenone, etc.), those of the 2-thio-2,5- thiazolidinedione series (i.e. the 2-thio-2,S (3H, 4H)- thiazoledione series) (e.g. 3-ethy1-2-thio-2,5-thiazo1idinedione, etc.), those of the 2,4-thiazolidinedione series (e.g. 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, 3 phenyl 2,4 thiazolidinedione, 3 a naphthyl 2,4- thiazolidinedione, etc.), those of the thiazolidinone series (e.g. 4athiazolidinone, 3-ethyl-4-thiazolidin0ne, 3-phenyl 4 thiazolidinone, 3 0c naphthyl 4 thiazolidinone, etc.), those of the 4-thiazolinone series (e.g. Z-ethylmercapto 4 thiazolinone, 2 alkylphenylamino 4- thiazolinones, 2 diphenylamino 4 thiazolinone, etc.), those of the 2-imino-2,4-oxazo1inone (i.e. pseudohydantoin) series, those of the 2,4-imidazolinedione (hydantoin) series (e.g. 2,4-imidazolinedione, 3-ethyl-2,4- imidazolinedione, 3 phenyl 2,4 imidazolinedione, 3-mnaphthyl 2,4 imidazolinedione, 1,3 diethyl 2,4- imidazolinedione, l ethyl 3 phenyl 2,4 imidazolinedione, l-ethyl 3 0c naphthyl-Z,4-imidazolinedione, l,3-diphenyl-2,4-irnidazolinedione, etc.), those of the 2-thio-2,4-imidazolinedione (i.e. 2-thiohydantoin) series (e.g. 2-thio-2,4-imidazolinedione, 3-ethyl-2-thio-2,4-imidazolinedione, 3 phenyl 2 thio 2,4 imidazolinedione, 3-u-naphthyl-2-thio-2,4-imidazolinedione, 1,3-diethyl 2 thio 2,4 imidazolinedione, 1 ethyl 3 phenyl 2 thio 2,4 irnidazolinedione, 1 ethyl 3 ocnaphthyl 2 thio 2,4 imidazolinedione, 1,3 diphenyl-2-thio-2,4-imidazolinedione, etc.), those of the 5-imidazolinone series (e.g. 2propy1mercapto-5-imidazolinone, etc.), etc. (especially a heterocyclic nucleus containing 5 atoms in the heterocyclic ring, 3 of said atom being carbon atoms, 1 of said atoms being a nitrogen atom, and 1 of said atoms being selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom).

In general, our dyes are produced by heating a mixture of a quaternary salt of Formula I with the appropriate intermediate. The reactants are heated to advantage in any of the suitable solvents used in dye syntheses, including solvents, such as, pyridine, glacial acetic acid, acetic anhydride, ethanol, propanol, dioxane, etc. to a temperature between room temperature and the reflux temperature of the solvent in the mixture. The reaction occurs advantageously in the presence of a basic condensing agent, such as an organic tertiary amine, e.g. triethylamine, tri-n-propylamine, triisopropylamine, tri-nbutylamine, etc. N-methylpiperidine, N-ethylpiperidine, N,N-dimethylaniline, N,N-diethylaniline, etc.

The symmetrical cyanine dyes of Formula II are prepared to advantage by heating a mixture of a compound of Formula I (in which R is methyl) With diethoxymethyl acetate (forms carbocyanine), trimethoxypropene (forms dicarbocyanine), l-anilino 5 phenylimino-l,3- pentadiene HCl (forms tricarbocyanine), etc. preferably in a suitable solvent and in the presence of a basic condensing agent.

The unsymmetrical cyanine dyes of Formula III are prepared advantageously by heating a mixture of a compound of Formula I (in which R is methyl) with a compound of the formula:

wherein R, Z, m and X are as defined previously and q represents an integer of from 1 to 2. This is preferably done in a suitable solvent and in the presence of a basic condensing agent.

The styryl dyes of Formula IV are prepared to advantage by heating a mixture of a compound of Formula I (in which R is methyl) with the appropriate N,N-disubstituted p aminobenzaldehyde, or N,N disubstituted p-aminocinnarnaldehyde preferably in a suitable solvent and in the presence of a basic condensing agent.

Our merocyanine dyes are made to advantage by heating a mixture of a compound of Formula I with a compound of formula:

VII

/'Q o=d o=w wherein Q is as defined previously and W represents a group selected from two hydrogen atoms or the group wherein 12 represents an integer of from 1 to 2, such that when the R group in Formula I is methyl, W represents the group or when R represents the S -anilinovinyl group, W represents two hydrogen atoms.

The syntheses of the following typical dyes will serve to illustrate but not limit our invention.

DYE 1 3,3'-dimethyl- 1, 1 '-diphenyllH-imidazo [4,5 -b] quinocarbocyanine iodide OBHS a s DYE 1 2,3-dimethyl 1 phenyl 1H imidazo[4,5-b]quinolinium p-toluenesulfonate (1 mol., 4.5 g.), diethoxymethyl acetate (1 mol. 700%, 6.5 g.), and triethylamine (1 mol., 1.0 g.) were dissolved in pyridine ml.), and the solution was heated under reflux for ten minutes. The dye was isolated as an oil after the addition of water to the reaction mixture. The oil was dissolved in methanol (50 ml.), and this solution was added to a solution of potassium iodide (4 g.) in water (50 ml.). The crude product was isolated by filtration. After boiling with acetone and recrystallization once from methanol, the yield of pure dye was 0.1 g. (3%), MP. 277.5278.5 C dec.

DYE 2 1,1',3,3'-tetraethyl-lH-imidazo[4,5-b]quinocarbocyanine iodide (EH5 CQHB I 1,3-diethyl 2 methyl-lH-imidazo[4,5-b]quinolinium iodide (1 mol, 1.5 g.) and diethoxymethyl acetate (1 mol. 300%, 1.3 g.) were dissolved in pyridine (10 ml.),

and the solution was heated under reflux for ten minutes The reaction mixture was cooled and the dye was precipitated by the addition of water (150 ml.). The dye suspension was chilled overnight, and the crude product was isolated by filtration. After one recrystallization from methanol, the yield of pure dye was 0.14 g. 11% M.P. 302.5303.5 C. dec.

DYE 3 1 ,3 3 -triethyl-1H-imidazo[4,5-b] quino-oxacarbocyanine iodide ([JzHs 1,3-diethyl 2 methyl 1H imidazo[4,5-b]quinolinium iodide (1 mol., 0.9 g.), 2 B acetanilidovinyl 3- ethylbenzoxazolium iodide (1 mol., 1.1 g.), and triethylamine (1 mol., 0.25 g.) Were dissolved in ethanol (10 ml.), and the solution was heated under reflux for twenty minutes. The reaction mixture was cooled, and the crude product was precipitated by the addition of water (150 ml.). The dye suspension was chilled overnight, and the crude product was isolated by filtration. After one recrystallization from methanol, the yield of pure dye was 0.1 g. (8%), MP. 245.0-246.0 C. dec.

DYE 4 1,3,3-triethyl-1H-imidazo[4,5-b1quinothiacarbocyanine iodide 1,3 diethyl 2 methyl 1H imidazo[4,5-b]quinolinium iodide (1 mol., 0.9 g.), 2 ,8 acetanilidovinyl 3- ethylbenzothiozolium iodide (1 mol., 1.1 g.) and triethylamine (1 mol.; 0.25 g. were dissolved in ethanol (10 ml.), and the solution was heated under reflux for ten minutes. The reaction mixture was cooled, and the dye was precipitated by the addition of water (150 ml.). The dye suspension was chilled overnight, and the crude product was collected by filtration. After two recrystallizations from methanol, the yield of pure dye was 0.3 g. (22% M.P. 251.0252.0 C. dec.

DYE 5 1, l ',3-triethyl-1H-imidazo[4,5--b] quino-2- carbocyanine iodide C H5 I 1,3-diethyl 2 methyl 1H irnidazo [4,5-b]quinolinium iodide (1 mol., 0.9 g.), 2 fi anilinovinyl 1 ethylquinolinium iodide (1 mol., 1.0 g.), acetic anhydride (1 mol. 0.5 g.), and triethylamine (1 mol. 100%, 0.75 g.) were dissolved in ethanol (10 ml.,) and the solution was heated under reflux for ten minutes. The reaction mixture was cooled, and the dye was precipitated by the addition of water ml.) The dye suspension was chilled overnight, and the crude product was isolated by filtration. After two recrystallizations from methanol, the yield of pure dye was 0.35 g. (26%), M.P. 265.5266.5 C. dec. (inserted at 180 C.).

DYE 6 3-ethyl-1',3,3'-trimethyl-l-phenyl-lH-imidazo [4,5-b]quinoindocarbocyanine iodide CH3 CH3 CaHs CH CgHs I 3-ethyl 2 methyl 1 phenyl 1H imidazo[4,5-b] quinolinium iodide (1 mol., 1.5 g.), Z-fl-acetanilidovinyl- 1,3,3-trimethyl 3H indolium iodide (1 mol, 1.6 g.), and triethylamine (1 mol., 0.36 g.) were dissolved in ethanol ml.), and the solution was heated under reflux for fifteen minutes. The reaction mixture was cooled, and the crude product was isolated by filtration, washed with acetone, and dried. After two recrystallizations from methanol, the yield of pure dye was 0.8 g. (39%), M.P. 312.5-3l3.5 C. dec. (inserted at 260 C.).

DYE 7 3,3'-diethyl-1, l '-diphenyllH-imidazo [4,5 -b] quinodicarbocyanine iodide 3-ethyl 2 methyl 1 phenyl 1H imidazo [4,5-b] quinolinium iodide (1 mol., 2.1 g.) and trimethoxypropene (1 mol. +100%, 0.65 g.) were dissolved in pyridine (15 ml.), and the solution was heated under reflux for thirty minutes. The reaction mixture was cooled, and the dye was precipitated by addition of water (150 ml.). The dye suspension was chilled overnight, and the crude product was isolated by filtration, washed with water, and dried. After one recrystallization from methanol, the yield of pure dye was 0.6 g. (32%), M.P. 264.5266.5 C. dec.

DYE 8 1,1',3,3'-tetraethyl-1H-imidazo[4,5-b] quinotricarbocyanine iodide 1,3 diethyl Z-methyl-lH-imidazo[4,5-b1quinolinium iodide (1 mol., 1.5 g.) and 1-anilino-5-phenylimino-1,3- pentadiene hydrochloride (1 mol., 1.2 g.) were dissolved in hot acetic anhydride. Triethylamine (1 mol., 0.4 g.) was added, and the solution was heated under reflux for ten minutes. The reaction mixture was cooled, and the crude product was precipitated by the addition of diethyl ether. After chilling, the ether was decanted. The residual semicrystalline gum was combined with 1,3-diethyl-2- methyl-1H-imidazo[4,5-b]quinolinium iodide (1 mol., 1.5 g.) and triethylamine (1 mol., 1.5 g.). This mixture was dissolved in ethanol ml.), and the solution was heated under reflux for twenty minutes. The reaction mixture was chilled, and the crude product was isolated by filtration,

washed with methanol, and dried. After one recrystallization from cresol and methanol, the yield of pure dye was 0.2 g. (7% M.P. 263.5264.5 C. dec.

DYE 9 2-p-dimethylaminostyryl-3-ethyll-phenyl-lH-imidazo [4,5-b1quinolinium iodide 3 ethyl-Z-methyl-l-phenyl-lH-imidazo[4,5-b1quinolinium iodide (1 mol., 1.5 g.), p-dimethylaminobenzaldehyde (1 mol. +50%, 0.8 g.), and piperidine (2 drops) were dissolved in ethanol 15 ml.), and the solution was heated under reflux for 2.5 hours. The reaction mixture was chilled overnight, and the crude product was isolated by filtration, washed with acetone, and dried. After two recrystallizations from methanol, the yield of pure dye was 0.3 g. (15%), M.P. 288.5289.5 C. dec. (inserted at 230 C.).

DYE 10 2-(4-p-dimethylaminophenyl-1,3-butadienyl) -3 -ethyll-phenyllH-irnidazo [4,5-b] quinolinium iodide CzHs I 3 ethyI-Z-methyl-l-phenyl-1H-imidazo[4,5-b]quinolinium iodide (1 mol., 1.5 g.) and p-dimethylaminocinnamaldehyde (1 mol.+50%, 0.95 g.) were dissolved in acetic anhydride (15 ml.), and the solution was heated under reflux for thirty minutes. The reaction mixture was chilled overnight, and the crude product was isolated by filtration, washed with acetone, and dried. After two recrystallizations from methanol, the yield of pure dye was 0.25 g. (12%), M.P. 261.5-2625 C. dec. (inserted at 230 C.).

DYE 11 3-ethyl-5- 1 ,3-diethyllH-imidazo [4,5 -b] quinol-2 3H) ylidene )ethylidene] -2-thio 2,4-oxazolidinedione 9 DYE 12 1 ,3-diethyllH-imidazo [4,5 -b] quinol-2- 3H -ylidene) ethylidene] -3-ethylrhodanine 1,3 diethyl Z-methyl-lH-imidazo[4,5-'b]quinolinium iodide (1 mol., 0.9 g.), 5-acetanilidomethylene-3-ethylrhodanine (1 mol., 0.75 g.) and triethylamine (1 mol., 0.25 g.) were dissolved in pyridine ml.), and the solution was heated under reflux for ten minutes. The reaction mixture was cooled and diluted with methanol (50 ml.) containing piperidine (5 drops). The solution was chilled, and the crude product was isolated by filtration. After two recrystallizations from pyridine and methanol, the yield of pure dye was 0.5 g. (50%), M.P. 249.0250.0 C. dec.

DYE 13 3-ethy1-5 (3-ethyll-phenyllH-imidazo [4,5 -b] quinol-2- (3H) -ylidene ethylidene] l-phenyl-Z-thiohydantoin C-N N I \=CHCH/ O=S \N/ N/ \N 2 [3 anilinovinyl-3-ethyl-1-phenyl-lH-imidazo [4,5-b] quinolinium iodide (1 mol., 1.4 g.), 3-ethyl-1-phenyl-2- thiohydantoin (1 mol., 0.6 g.), acetic anhydride (1 mol. +20()%, 0.8 g.), and triethylamine (1 mol. +200%, 1.1 g.) were dissolved in ethanol ml.), and the solution was heated under reflux for fifteen minutes. The mixture Was chilled overnight, and the crude product was isolated by filtration, washed with methanol, and dried. After two recrystallizations from pyridine and methanol, the yield of pure dye was 0.8 g. (57%), M.P. 225.5226.5 C. dec.

DYE 14 1-ethy1-5-[ (3-ethyll-phenyl-lH-imidazo [4,5 -b] quinol- 2 3H) -ylidene) ethylidene] -2-thiobarbituric acid 2 13 anilinovinyl-3-ethy1-l-phenyl-lH-imidazo[4,5-b] quinolinium iodide (1 mol., 1.75 g.), 1-ethyl-2-thiobarbituric acid (1 mol., 0.6 g.), acetic anhydride (1 mol. +130%, 0.8 g.), and triethylamine (1 mol. +130%, 1.15 g.) were dissolved in ethanol (15 ml), and the solution was heated under reflux for fifteen minutes. The mixture was chilled overnight, and the crude product was isolated by filtration, washed with methanol, and dried. After tWo recrystallizations from pyridine and methanol, the yield of pure dye was 1.2 g. (87%), M.'P. 310 C.

DYE 15 5- 3-ethyll-phenyllH-imidazo [4,5 'b] quino1-2( 3-H) ylidene) ethy1idene]-3-pheny1-2,4 thiazolidinedione 2 B anilinovinyl-3-ethyl-l-phenyl-lH-imidazo[4,5-b] quinolinium iodide (1 mol., 1.4 g.), 3-phenyl-2,4-thiazolidinedione (1 mol., 0.55 g.), acetic anhydride (1 mol. +200%, 0.8 g.), triethylamine (1 mol. +200%, 1.1 g.) were dissolved in ethanol (15 mL), and the solution was heated under reflux for fifteen minutes. The reaction mixture was chilled overnight, and the crude product was isolated by filtration, washed with methanol, and dried. After two recrystallizations from pyridine and methanol, yield of pure dye Was 0.55 g. (42%), M.P. 300 C.

DYE 16 3-carboxymethyl-5- (3-ethyl- 1-phenyl-1H-imidazo[4,S-b] quinol 2 3H) -ylidene) ethylidene] -2-thio-2,4-oxazolidinedione caHs El) $H2COOH 2 ,8 anilinovinyl-3-ethyl-1-phenyl-lH-imidazo[4,5-b] quinolinium iodide (1 mol., 1.7 g.), 3-carboxyrnethyl-2 thio-2,4-oxazolidinedione (1 mol. 1.2 g.), acetic anhydride (1 mol. +200%, 1.0 g.), and triethylamine (1 mol. +200%, 1.3 g.) were dissolved in ethanol (15 ml.), and the solution was heated under reflux for twenty minutes. The reaction mixture was diluted with glacial acetic acid (40 drops) and anhydrous ether and chilled. The ether was decanted, and the residual oil was boiled with methanol (10 ml.). Glacial acetic acid was added, and after chilling overnight, the crude product was isolated by filtration, washed with methanol, and dried. After two recrystallizations carried out by dissolving the product in hot methanol containing triethylamine followed by acidification with acetic and chilling, the yield of pure dye was 0.25 g. (16%), M.P. 247.0 249.O C. dec.

DYE 17 5-[(3-ethy1-l-phenyl-lH-imidazo [4,5 b]quinol 2( 3H) ylidene) ethylidene]] -3-(2-sulfoethyl)-2-thio 2,4 oxazolidineone (fans omornsom N o1ar-on-x 0=s 2 13 anilinovinyl 3 ethyl-l-phenyl-1H-imidazo[4,5- b]quinolinium iodide (1 mol., 1.7 g.), 3-(2-sulfoethyl)-2- thio-2,4-oxazolidinedione (1 mol. +50%, 1.1 g.), acetic anhydride (1 mol. +200%, 1.0 g.), and triethylamine (1 mol. +200%, 1.3 g.) were dissolved in ethanol 15 ml.), and the solution was heated under reflux for twenty minutes. The reaction mixture was cooled to room temperature and concentrated hydrochloric acid (40 drops) was added. The solution was chilled overnight and the crude product was isolated by filtration and dried. After two recrystallizations carrried out by dissolving the dye in hot methanol containing triethylamine, followed by precipitation by the addition of methanol containing hydrochloric acid, the yield of pure dye was 0.65 g. (37%, M.P. 291.5292.5 C. (dec. inserted at 230 C.).

DYE 18 3-ethyl-5-[ (3ethyll-phenyl- 1 H-imidazo [4,5 -b] quinol- 2 (3H) -ylidene) 2-butenylidene1rhodanine 3 ethyl-Z-methyl-l-phenyl-lH-imidazo[4,5-b]quinolinium iodide (1 mol., 1.25 g.), 5-acetanilidoallylidene-3- ethylrhodanine (1 mol., 1.0 g.), acetic anhydride (excess, 0.6 g.), and triethylamine (excess, 0.6 g.) were dissolved in pyridine ml), and the solution was heated under reflux for fifteen minutes. The reaction mixture was chilled and diluted with methanol (75 ml.). The solution was chilled overnight, and the crude product was isolated by filtration, washed with methanol, and dried. The product was recrystallized once from pyridine and methanol containing piperidine and then extracted four times with small portions of ligroin (B.P. 100115 C., 50-65 m1. portions). After one recrystallization from a large amount of ligroin (B.P. 100115 C.), the yield of purified dye was 0.15 g. (6%), M.P. 235.5236.5" C: dec.

The following synthesis will illustrate the preparation of representative imidazo[4,5-b1quinolinium salts of our invention.

2B-anilinovinyl-3-ethyl-l-phenyl-1H-iniidazo[4,5-b] quinolinium iodide N N C3115 3-ethyl-2-methyl 1 phenyl-lH-imidazo[4,5-b]quinolinium iodide (1 mol, 6.6 g.) and ethyl isoformanilide (1 mol. 400%, 12.0 g.) were dissolved in n-butanol ml.), and the solution was heated under reflux for thirty minutes. The reaction mixture was chilled overnight. The crude product was isolated by filtration, washed repeatedly with anhydrous ether, and dried. After one recrystallization from methanol, the yield of pure dye was 6.15 g. (75%), M.P. 263.0264.0 C. dec.

2,3-dimethyl-1-phenyl-lH-imidazo [4,5-15] quinolinium p-toluene-sulfonate CH p-toluenesulfonato 2,3-din1ethyl 4 oxo-l-phenyl 2 imidazolinium ptoluenesulfonate (1 mol., 3.6 g.), o-aminobenzaldehyde (1 mol, 1.2 g.), and glacial acetic acid (15 ml.) were mixed and heated under reflux for 2.2 hours. The reaction mixture was concentrated to dryness under reduced pressure. After mixing the residue with benzene, the benzene was removed under reduced pressure. The product was isolated as a non-crystalline glass. This product was used, without further purification, in dye condensations. 3-ethyl-2-methyl-l-phenyl-1H-imidazo[4,5-b] quinolinium iodide 3-ethyl 2 methyl-4-oxo-1-phenyl 2 imidazolinium iodide (1 mol., 13.2 g.), o-aminobenzaldehyde (1 mol., 4.8 g.), and glacial acetic acid 30 ml.) were mixed and heated On a steam bath for 3.5 hours. The hot reaction mixture was poured into a solution of potassium iodide (6.4 g.) in water ml.), and the resulting mixture was cooled overnight. The water was decanted, and the residual oil was stirred repeatedly with ether. The oil was then crystallized from ethanol, isolated by filtration, and dried. After two recrystallizations from ethanol, the yield of pure product was 2.9 g. (18%), M.P. 230.5232.5 C.

1 ,3-diethyl-2-meth yl- 1 H-imidazo [4,5 -b] quinolinium iodide 1,3 diethyl-2-methyl-4-oxo-2-irnidazolinium iodide (1 mol. 20%, 50.8 g.) was dissolved in hot glacial acetic acid (20 ml.). o-Aminobenzaldehyde (1 mol., 18.2 g.) was added to the solution followed by glacial acetic acid (10 ml), and the mixture was heated on a steam bath for 3.2 hours. The hot reaction mixture was poured with stirring into boiling water (250 ml.). The hot solution was filtered, and potassium iodide g.) was dissolved in the filtrate. The crude product precipitated from the aqueous solution upon cooling and was collected by filtration. After drying, the product was boiled with acetone. The acetone mixture was cooled, filtered, and the precipitate was washed with acetone and dried. Recrystallization from ethanol gave 9.4 g. (17%) of straw-colored needles, M.P. 186.0187.5 C.

The imidazolinium salts used to prepare our new imidazo [4,5-b]quinolinium salts were prepared by conventional methods from the parent 2-imidazolin-4-ones made as described by Brunken and Zeh in German Patents 8,052 and 9,740, both issued in 1955.

For the preparation of photographic emulsions, the new dyes of the invention are advantageously incorporated in the washed, finished silver halide emulsion and should, of course, be uniformly distributed throughout the emulsion. The methods of incorporating dyes in emulsions are relatively simple and well known to those skilled in the art of emulsion making. For example, it is convenient to add the dyes from solutions in appropriate solvents, in which the solvent selected should have no deleterious effect on the ultimate light-sensitive materials. Methanol, isopropanol, pyridine, etc., alone or in combination have proven satisfactory as solvents for the majority of our new dyes. The type of silver halide emulsions that are sensitized with our dyes include any of those prepared with hydrophilic colloids that are known to be satisfactory for dispersing light-sensitive silver halides, for example, emulsions prepared with hydrophilic colloids, such as, natural materials, e.g., gelatin,

13 albumin, agar-agar, gum arabic, alginic acid, etc., and synthetic hydrophilic resins, e.g., polyvinyl alcohol, polyvinyl pyrrolidone, cellulose ethers, partially hydrolyzed cellulose acetate, etc.

The concentration of our new dyes in the emulsion can vary widely, i.e., from about to about 100 mg. per liter of flowable emulsion. The specific concentration will vary according to the type of light-sensitive material in the emulsion and according to the effects desired. The most advantageous dye concentration for any given emulsion can be readily determined by making the tests and observations customarily used in the art of emulsion making.

To prepare a gelatino-silver halide emulsion sensitized with one of our new dyes, the following procedure is satisfactory: A quantity of the dye is dissolved in a suitable solvent, and a volume of this solution containing from 5 to 100 mgs. of dye is slowly added with intimate mixing to about 1,000 cc. of a gelatino-silver halide emulsion. With most of our dyes, to mgs. of dye to any emulsions in which a part or all of the gelatin is substituted by another suitable hydrophilic colloid such as previously mentioned.

The above statements are only illustrative and are not to be understood as limiting our invention in any sense, as it will be apparent that our dyes can be incorporated by other methods in many of the emulsions customarily used in the art. For instance, the dyes can be incorporated by bathing a plate of film bearing an emulsion, in a solution of the dye.

Photographic silver halide emulsions, such as those listed above, containing the sensitizing dyes of our invention can also contain such addenda as chemical sensitizers, e.g. sulfur sensitizers (e.g. allyl thiocarbamide, thiourea, allylisothiocyanate, cystine, etc.), various gold compounds (e.g. potassium chloroaurate, auric trichloride, etc.) (see U.S. Patents 2,540,085; 2,597,856 and 2,597,915), various palladium compounds, such as palladium chloride (U.S. 2,540,086), potassium chloropalladate (U.S. 2,598,079), etc., or mixtures of such sensitizers; antifoggants, such as ammonium chloroplatinate (U.S. 2,566,245), ammonium chloroplatinite (U.S. 2,566,263), benzotriazole, nitrobenzimidazole, 5- nitroindazole, benzidine, mercaptans, etc. (see Mees The Theory of the Photographic Process, Macmillan pub., page 460), or mixtures thereof; hardeners, such as formaldehyde (U.S. 1,763,533), chrome alum (U.S. 1,763,533), glyoxal (U.S. 1,870,354), dibromacrolein (Br. 406,750), etc.; color couplers, such as those described in U.S. Patent 2,423,730, Spence and Carroll U.S. application 771,380, filed Aug. 29, 1947 (now U.S. Patent 2,640,776), etc.; or mixtures of such addenda. Dispersing agents for color couplers, such as those set forth in U.S. Patents 2,322,027 and 2,304,940, can also be employed in the above-described emulsions.

The following example will serve to further illustrate our invention by showing the sensitizing effects of representative dyes of our invention on silver halide emulsions.

Our emulsions are coated to advantage on any of the materials used for photographic elements including, for example, paper, glass, cellulose acetate, cellulose nitrate, synthetic film-forming resins, e.g., the polyesters, the polyamides, polystyrenes, etc.

The following example will serve to further illustrate our invention by showing the sensitizing effects of representative dyes of our invention on silver halide emulsions.

14 EXAMPLE 1 Sensitizing amounts of the dyes (indicated in the following table), dissolved in suitable solvents, were each added to separate portions of a gelatino-silver halide emulsion (silver bromoiodide or silver chlorobromide). After digestion at 50 C. for 10 minutes, the emulsions were coated at a coverage of 432 mg. of silver per square foot on cellulose acetate film support. A sample of each coating was exposed with an IB type sensitometer and to a wedge spectrograph, processed for 4 minutes in a conventional developer, fixed in the usual way, Washed and dried. The following table lists the sensitizing range and sensitizing maximum (both in mg) produced in the emulsions with our representative dyes.

Sensitizing Sensitizing Silver halide in range maximum emulsion in 111;; in mp Dye:

1 Silver bromoiodide 520-665 1 600 d To 680 630 To 615 550 To 670 590, 630 To 720 580, 670 510-625 590 620-760 710 To 730 585 To 730 To 630 570 12 d0 To 680 610 13 Silver ch1orobromide To 640 545, 585

do To 580 5 d0 400-630 0 llverbr To 600 520, 570 do T0635 570 18 Silver chlorobromide. 560-750 70 0 1 Ghost at 655. 2 Not definite.

The new imidazo[4,5-b]quinoliniurn salts of our invention are valuable for making photographic silver halide sensitizing dyes of the cyanine type, styryl type and merocyanine type. These dyes are valuable for extending the light-sensitivity of the silver salide emulsions to longer wavelengths.

The invention has been described in detail with particular reference to preferred embodiments thereof but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A compound having the formula:

wherein R represents an alkyl hydrocarbon group having 1 to 18 carbon atoms, cyclohexyl, benzyl, phenethyl, phenyl, tolyl or chlorophenyl, R represents an alkyl hydrocarbon group having 1 to 18 carbon atoms, a carboxyalkyl group having 1 to 4 carbon atoms in the alkyl portion, a sulfoalkyl group having 1 to 4 carbon atoms or cyclohexyl, R represents methyl or ,B-anilinovinyl and X represents an acid anion.

2. A compound in accordance with claim 1 wherein R represents ethyl or phenyl, R represents methyl or ethyl, R represents methyl or ,B-anilinovinyl and X represents an acid anion.

3. A compound in accordance with claim 1 wherein said compound is 1,3-diethyl-2-methyl-lH-imidazo [4,5- b]quinolinium iodide.

4. A compound in accordance with claim 1 wherein said compound is 3-ethyl-2-methyl-l-phenyl-lH-imidazo [4,5-b] -quinolinium iodide.

5. A dye selected from the dyes having the formulas:

wherein R represents an alkyl hydrocarbon group having 1 to 18 carbon atoms, cyclohexyl, benzyl, phenethyl, phenyl, tolyl or chlorophenyl, R represents an alkyl hydrocarbon group having 1 to 18 carbon atoms, a carboxyalkyl group having 1 to 4 carbon atoms in the alkyl portion, a sulfoalkyl group having 1 to 4 carbon atoms or cyclohexyl, R represents an alkyl hydrocarbon group having 1 to 5 carbon atoms, benzyl, fl-hydroxyethyl or 5- acetoxyethyl, n represents an integer of from 2 to 4, X represents an acid anion, Z represents the nonmetallic atoms required to complete a thiazole nucleus, a Demothiazole nucleus, 21 naphthothiazole nucleus, a thianaphtheno-7,6,4,5-thiazole nucleus, an oxazole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, a selenazole nucleus, a benzoselenazole nucleus, a naphthoselenazole nucleus, a thiazoline nucleus, a Z-quinoline nucleus, a 4-quinoline nucleus, a l-isoquinoline nucleus, an imidazole nucleus, a benzimidazole nucleus, a naphthimidazole nucleus, a 3-isoquinoline nucleus, at 3,3-di(low carbon alkyl hydrocarbon) indolenine nucleus, a Z-pyridine nucleus or a 4-pyridine nucleus; R and R each represents an alkyl hydrocarbon group having 1 to 6 carbon atoms or Z-cyanoethyl, m represents an integer of from 1 to 2; and Q represents the nonmetallic atoms required to com plete a Z-pyrazolin-S-one nucleus, an isoxazolone nucleus, an oxindole nucleus, a 2,4,6-triketohexahyd ropyrimidine nucleus, a rhodanine nucleus, 8. 2(3H)-imidazo[1,2-a] pyridine nucleus, a 5,7-dioxo-6,7-dihydro-5-thiazolo [3,2-a]pyrirnid.ine nucleus, 9. 2-thio-2,4-oxazolidinedione nucleus, a thianaphthenone nucleus, a 2thio-2,5-thiazolidinedione nucleus, a 2,4-thiazolidinedione nucleus, a thiazolidinone nucleus, a 4-thiazolin0ne nucleus, a Z-imino-2,4-oxazolinone nucleus, a 2,4-imidazolinedi0ne nucleus, a 2-thio-2,4-imidazolinedione nucleus or a S-imidazolinone nucleus; and d represents an integer of from 2 to 3.

6. A cyanine dye in accordance with claim 5 having the formula designated 1.

7. A dye compound in accordance with claim 5 wherein said dye compound is 1,1,3,3-tetraethyl-lH-imidazo [4,5 -b] -quinocarbocyanine iodide.

8. A cyanine dye in accordance with claim 5 having the formula designated II.

9. A dye compound in accordance with claim 5 wherein said dye compound is 1,3,3-triethyl-1H-imidazo[4,5- blquinooxacarbocyanine iodide.

10. A merocyanine dye in accordance with claim 5 having the formula designated IV.

11. A dye compound in accordance with claim 5 wherein said dye compound is 3-etl1yl-5-[(1,3-diethyl-1H-imidazo[4,5-b] -quinol-2(3H)-ylidene)ethylidene] 2 thic- 2,4-oxazo1idinedione.

12. A dye compound in accordance with claim 5 wherein said dye compound is 1-ethyl-5-[(3-ethyl-1-phenyl-1H- imidazo [4,5]quinol-2(3H)-ylidene)ethylidene] -2-thiobarbituric acid.

13. A dye compound in accordance with claim 5 wherein said dye compound is 5-[(3-ethyl-1-pheny1-1H- imidazo [4,5-b]quinol-2(3H)-ylidene)ethylidene] 3 -(2- sulfoethyl) -2-thio-2,4-oxazolidinedione.

References Cited Dornow et al., Chemiches Ber., vol. 91, pp. 1834 to 1835 (1958).

Chemical Abstracts, vol. 55, C015. 4507 to 4508 (1961) (abstract of Sabata et 211.).

JOHN D. RANDOLPH, Primary Examiner US. Cl. X.R.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 I83l96. Dated 12/9/69 Inventofls) Philip W. Jenkins and Leslie G. S. Brooker It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

should read --pyridone--- GEL Elihu S; TALE 4 Anest:

Edward m. Fletcher, 1r- Amfingo mm B. sownm, m. Oomisaionor c1 Paton 

